Under pressure at the SEMA Show: Dealers raise practical questions about TPMS: the impact of aftermarket rims, system compatibility, and what to do if your customer doesn't want to pay for it

Dec. 1, 2006

All light vehicles built after Sept. 1, 2007, will come from the factory with tire pressure monitoring systems, complete with a malfunction indicator lamp. That means if tire pressure monitoring systems aren't already a fact of life at your business, they soon will be.

And how you service those systems will spell the difference between your continuing success and the complaints of unhappy customers, which could very well take the form of legal action.

That's the message tire pressure monitoring system (TPMS) experts hammered home during three TPMS panel discussions at last month's SEMA (Specialty Equipment Market Association) Show.

Practical matters

TPMS may be here to stay, but the rules of the game are still being written, according to Kevin Rohlwing, senior vice president of education and technical services for the Tire Industry Association.

"The answer to every TPMS question is: 'It depends,'" he says. (For more about this, see Rohlwing's article on intelligent tire technology in this archive).

Tire dealers who attended the three TPMS seminars voiced a number of questions, which Rohlwing and representatives from several aftermarket TPMS manufacturers, including Schrader Electronics Ltd. and Siemens VDO, answered.

A wide range of practical TPMS-related topics were covered, from the legal havoc that disabling a system could create to how tire sealants affect TPMS sensors. Here's a look at the topics that were discussed. (Schrader was represented by Carl Wacker, its vice president of sales and marketing, while Siemens was represented by Jean-Claude Deniau, one of its technical specialists.)


On intentionally disabling a vehicle's TPMS:

Rohlwing: The Federal Motor Carrier Safety Standards... are very specific as to what can or cannot be done. But knowingly making a system inoperative is knowingly making it inoperative, and if you do it, it's going to be used against you. That's where consumer education becomes so important.

You are the expert. There is no way the consumer can release you from that liability. You can get a videotaped testimonial from the consumer (that he asked you to disable his TPMS), but if the guy goes out and kills himself, his widow and kids don't care.

On custom wheels and TPMS:

Wacker: There are so many (aftermarket wheels) that have non-compliant holes by Tire & Rim Association standards. You want to keep air inside the tire. If (a rim) is not compliant with the standard, all bets are off.

Rohlwing: This is the Pandora's Box of TPMS. The TREAD (Transportation Recall Enhancement, Accountability and Documentation) Act is very specific about what the consumer can choose to substitute other equipment that will allow TPMS to resume normal function. The point there is, if you return the original wheels with the original sensors to the consumer and get them to sign off on the fact that they received them, this is where you protect yourself.

Give them back their original rims with their original sensors and get them to document, "Yes, I understand that my TPMS doesn't work and if I want my TPMS to resume normal functioning, I'm going to have to go back to either my original rims and sensors or a different set of aftermarket rims that will accommodate the sensors."


On how changing rim diameters will affect sensors:

Deniau: There are no issues. The only thing that will change is the time the sensor comes on. What the sensor does is read pressure and transmit information.

On inter-system compatibility:

Deniau: If you're using sensors that were designed for General Motors and put them on a Ford vehicle, it won't work. If you have a BMW, it has its own protocol. (Another OEM vehicle) may have its own protocol. Because of the history of TPMS, there has been a divergence of protocol and a divergence of systems.

Rohlwing: That's one of the big black holes. There are still a lot of vehicles out there that have no TPMS re-learn procedures, so you have to go through the manufacturer. If you're on ALLDATA or Mitchell OnDemand, that information should be available through them.

On customers who don't want TPMS but ask you to mount a spare instead:

Rohlwing: In the instance of a full-size spare, it's still going to be considered temporary. The phrase that's going to be interpreted by the court is "Knowingly make inoperable." Pre-qualifying the vehicle before you change or service the tire is going to be an important step in the process.

On diagnosing TPMS malfunctions:

Rohlwing: If a system is inoperable, it's going to flash. If you start the car and see the light flash, (I suggest you) turn the car off, go back inside and inform the customer, "You have an inoperable TPMS. There is a malfunction. We're not going to let your vehicle leave this dealership until it's repaired." (Whether you are required by law to repair an inoperable tire pressure monitoring system or not is still open to interpretation.)

I know (dealers) who actually have a release form that the consumer must sign... that says, "I understand that I am responsible for all charges to repair this TPMS and that I will not have my car returned to me until the TPMS is repaired." Some consumers just choose to drive away. That's a lawsuit that just went to somebody else.

Wacker: Don't think of TPMS as an idiot light. Consider it, in most cases, like a fuel gauge. It's telling you how much air you've got in your tires and whether or not you're safe riding down the road.


On how many TPMS parts you should stock:

Wacker: Because there was a life before NHTSA (the National Highway Traffic Safety Administration) and a life after NHTSA with TPMS, there are a lot of vehicles that are pre-NHTSA. We ended up with all these varieties (of systems). You guys are going to see all the things (the system manufacturers) have made since 1995. There are at least 30 or 40 part numbers right now.

On re-programming thresholds:

Rohlwing: The only person who can re-program the threshold is the vehicle manufacturer. The aftermarket cannot re-program the threshold.

On the use of tire sealants with TPMS:

Wacker: If you plug a hole (in the sensor), you're no longer reading pressure and you can get a (faulty) reading. If it plugs the port, you'll get an erroneous reading.

On the effect of nitrogen on TPMS:

Wacker: The air you breathe is 78% nitrogen. The sensor doesn't care whether it's nitrogen or propane.


Panelists also discussed the economies of TPMS. Over time, sensor prices will drop as the technology becomes more commonplace, according to Rohlwing.

Dealers should charge for what TPMS products and service are worth, he says, but also must make sure customers know what they're in for.

"You've made a tremendous investment in TPMS. This is something you shouldn't have to give away.

"Educate the customer as to why they are being charged before they are charged. If you're going to charge for TPMS, you need to communicate this with the customer" before service work takes place.